Hi everyone! This update is relatively recent, and has been mentioned other places, but I still wanted to bring it to everyone's attention here to help with Doronicum ID locally. A voucher from the Cedar River Trail in Maple Valley had been languishing in our herbarium for over 20 years stuck at genus, and our riparian specialists have been noticing its prolific movement downstream with greater-density colonies since larger disturbance/flooding events (especially those of 2020). Here is the old voucher and initial location information:

https://www.inaturalist.org/observations/205448699

and the same population 22 years later with help from @uff-da:

https://www.inaturalist.org/observations/206805873

Willdenow's leopard-bane or Doronicum x willdenowii

D x willdenowii (D pardalianches x D. plantagineum) in New Flora of the British Isles 2nd Ed (Stace).

Description: Short, glandular hairs with a few long eglandular hairs on petioles of basal leaves. Basal leaf bases are mostly rounded-truncate (sometimes slightly cuneate) and leaf margins are most often obscurely crenate-dentate (though there is a range of phenotypic expression within this population). Basal leaf shape is also obtuse (as opposed to acute). Combine this with the number of capitula (inflorescences)- which is usually less than but rarely more than 3! Locally common and naturalized within riparian forest in shady understory along both sides of Cedar River from Maple Valley down to Renton. Alnus rubra overstory, growing with Rubus bifrons, Alliaria petiolata, Hesperis matronalis, Ranunculus repens.

This one is now in the WTU Burke (UW) Herbarium:
https://www.inaturalist.org/observations/121826591

This one is represented in the WTU image collection:
https://www.inaturalist.org/observations/187311875

While impacts are understudied locally and generally rely on anecdotal observations, Doronicum is in Senecioneae and contains pyrrolizidine alkaloids (like ragwort and european coltsfoot) that impact forage, browse, and water quality (and honey quality!). D x wildenowii has a tuberous caudex and short, brittle rhizomes that can break off and form new plants. Basal leaves are the best way to ID and generally aren't the most intact by the time the plant is blooming. Doronicum sp. is on the NWCB monitor list but looks like the species being monitored in Skamania County is most likely D pardalianches given the leaf shape of the base of the basal leaves appear cordate (heart-shaped):
https://www.nwcb.wa.gov/weeds/leopards-bane

There is one other observation by Frank Lomer in BC that wasn't accessible when me and @echaley were looking at this but is now linked with these in the consortium of pnw herbaria. Also considered a "neophyte" in Belgium where it has also spread from cultivation and naturalized. Fun excerpt from a Scottish Newsletter 2022 from the Botanical Society of Britain & Ireland (2nd paragraph on p.18):
https://issuu.com/bsbi/docs/sn-2022/18

From Cambridge University Botanic Garden, where it is referred to as an "invasive species in northern Europe."

All Doronicum spp. are also on Bellevue Botanical Gardens' "prohibited" list even though one of the parents (D. plantagineum) has found its way there... https://www.inaturalist.org/observations/207276779

Many thanks to the botanical experts within the noxious weeds and consortium of PNW Herbaria-verse- especially the botanist @matt_mardigan for his early observations and David Giblin, UW herbarium, for his expertise. Please post any leopards bane you're seeing out in the world, especially King County so we can get it in this project and continue to learn about it! Thanks for keeping the observations coming and following!

Tom
terler@kingcounty.gov

Posted on May 21, 2024 10:40 PM by tomerler